Many computers today are assembled from components built to one or more industry standards. The use of standardized components using specific interfaces allows for ease of supply, efficiency in production, and competitiveness in pricing. A further advantage associated with the use of standardized computer components, as opposed to custom pieces, is that of performance.
The dollar-for-dollar performance advantage of many standardized components over similar custom components can be viewed as a beneficial consequence of the balance between the resources invested in each product and the efforts to optimize its function. Standardized components have higher sales volume and return potential than custom components, thereby generally allowing additional resources to be invested in their production. Standardized components also face broader competition regarding performance. Therefore, if sales are to be made at a given price point, the performance of the corresponding standardized component must excel.
In contrast, even when custom components are desired, it is often not economically feasible to optimize performance. The paramount concern is to meet the specific needs calling for the customization. This is particularly so when space conservation is the primary consideration. Although the number of smaller computers available for duty where space conservation is important has increased, they are typically very expensive. Also, these smaller custom computer systems often suffer in the areas of computing speed and system reliability relative to computers using less costly standardized components.
It should be noted, however, that additional factors affect the performance of existing space-saving computer systems. The compaction of layout in shrinking main board sizes results in component crowding and imparts additional design constraints which hinder design for optimal performance. Crowding can adversely affect the manner in which components are connected as well as result in significant heat dissipation problems. Further compromises are often made in shrinking computer sizes. To conserve space, smaller fans or fewer fans may be included in a design. Also, custom-made power supplies and data drives may be required in producing a compact system. As with main boards designed for small size, these units often lag in performance relative to their standardized counterparts.
The use of custom components introduces further difficulties when they break down. Supply issues can be such a difficulty as to make it more feasible to replace an entire machine so as not to lose its computing power for an extended time, rather than wait for repair components necessary to get the existing machine up and running. This difficulty is often compounded by an increased failure rate experienced with custom components.
All of these disadvantages aside, there exists a need for compact computer systems in the server industry. It is this very need which has justified acceptance of current compact systems despite their performance and thermodynamic disadvantages. Especially with the advent and rise of the Internet and World Wide Web, an increasing demand for more computers to be connected to serve as network hosts or servers has arisen.
The function of network serves may be carried out by more traditional “servers” in the form of powerful computers usually configured to perform specific functions. Another more recently developed model in providing network services is with grouped computers or “modules” linked, in part, through software such as the VNC software package available through Oracle, Inc., to form a “farm” or “puzzle” of computers working together. Computers set up in a farm or otherwise provided in a coordinated set will include their own processors, data drives and so-forth in order that each may accomplish a fraction of the work intended for the whole.
Farms, in particular, have several advantages over typical servers. One advantage is the combined speed of processors working together in a coordinated manner. Another advantage resides in the redundancy of a farm's structure. If any one module fails, it can be extracted or replaced with no ill effect other than the fractional loss of the farm's capacity. Put another way, failure of part the set of computers does not shut down the whole. In contrast, when any portion of a server fails, the whole system may go down. If the failure itself does not cause the loss, shutting down the computer for a necessary repair certainly will.
Irrespective of the type of network host that might be employed, it is clear that there is a growing need for compact, serviceable network resources. This has lead to an increasing need for space in which to house the network host units and a consolidation of spaces where they are located. Sites known as co-location sites where numerous networked computers find a home now exist. Space for the computers is typically rented at such sites. Rent calculations may be based on the overall space occupied, power consumption and bandwidth handled by the computers occupying the space. Because of the relationship between such factors, it will often be in favor of both a co-location site and computer service provider to maximize both the density and performance efficiency of the computers at a given site. By increasing the density at which computers may be packed into a given area, the service provider benefits since less space is required for a given number of computers; the co-location site benefits since the ultimate bandwidth available in association with the space available may be greatly increased.
Other less apparent benefits stem from conserving the space a host computer occupies. In many instances, it will be economically feasible to forestall the retirement of otherwise outdated host computers since the cost of the space they occupy is relatively lower, thereby justifying their continued service for a period of time. On the other hand, where it is preferred to only maintain the highest-end computers in service, the savings available by minimizing the size of such computers without hindering performance is quite clear. There exists a need for computer systems adapted for realizing these many advantages.
Typically, at a site where numerous computers are connected to a network, the computers are provided stacked in racks arranged in repeating rows or cells. Access to the computers is necessary for servicing, upgrading hardware, loading software, attaching cables, switching power on and off, and so forth. The elimination of as much access space as is feasible can increase the density of computer systems that may be provided for a given square footage of area at a site. Moveable rack solutions can be used to decrease access space requirements. However, they have not gained wide acceptance. Consequently, there exists a need to eliminate extraneous access space while still maintaining the use of relatively inexpensive, standard (or more-or-less standard) racks.
A rack that is currently being widely used measures roughly 19 inches wide, 30 inches deep and 74 inches high. In at least one co-location site, these racks are lined up in rows of roughly 10-30 units with access doors on each side of a rack. Access aisles are provided on both sides of the rows. Many of the racks are filled with cumbersome computers mounted on sliders which are attached through mounting holes provided in the front and back of the rack. Regardless of the chassis design of the computers (or lack thereof where computers are merely built on open trays with their components uncovered) and how they are mounted to the racks, data devices included in the computer are accessed from the front. Main board I/O's, other I/O's, power cords and such items are typically accessed from the back. It is this latter design aspect which not only results in inefficiency in the amount of access space required, but also in the frequent inefficiencies associated with having to administer services to both sides of a computer. Consequently, there exists a need for computers useable in a network setting that are accessible and fully serviceable from a single side.
In order to significantly increase the density at which computers in a given space are provided, the only solution to date has been to shrink the computer's box. As such, there exists a need to increase the density at which computers may be provided in a given space by what means are possible while still having the ability to utilize standardized components. Aspects of the present invention including single-sided access help in this regard.
Additionally, there exists a need for improved cooling of computers, especially where large numbers are provided. This need is compounded by increased computer density. Features of the invention help meet this need as well. In certain situations, this need to maintain acceptable computer temperatures can compete with the need to maintain the environment in which the computers are housed at an acceptable temperature without exorbitant expenditures for environmental cooling. Certain features of the invention directed at cooling the computers help in this regard.